WASHINGTON—Rep.
Gregg Harper,
a Mississippi Republican and chairman of the House Administration Committee, will retire at the end of the year and won’t seek a sixth term. He is the 27th House Republican to announce his retirement during this Congress.

Mr. Harper, 61, cited a desire to leave Congress to be with his family, including an adult son who has special needs and his daughter who is expecting her first child.

“We have been contemplating for almost two years when it would be our time not to run again, and after spending time over Christmas and New Year’s with my family, we made the very difficult decision to say that 10 years will be long enough,” Mr. Harper said in a statement. “I never intended for this to be a career, and it will soon be time for another conservative citizen legislator to represent us.”

Since 1976, an average of 22 House members have retired each two-year cycle without seeking another office, according to
Nathan Gonzales,
publisher of Inside Elections, which analyzes the House and Senate. While some members have said they are leaving after the current session because they are facing tough races, Mr. Harper won 66% of the vote in 2016 and his district is considered safely Republican. President
Donald Trump
won it by more than 20 points.

Austin Barbour,
a Mississippi-based campaign strategist, called Mr. Harper’s announcement “surprising news for anyone paying attention to Mississippi politics. Gregg is a wonderful man who is so well thought of throughout the state. He could have stayed in that seat as long as he wanted.”

In November, Mr. Harper was tapped by House Speaker
Paul Ryan
(R., Wis.) to conduct a comprehensive review of sexual-harassment policies in the House, after it was revealed that members had used taxpayer funds to settle harassment claims against them. Mr. Harper said in an interview last month that he plans to release this month legislation revising the chamber’s policies on the issue.

Mr. Harper is the sixth committee chair to announce a retirement at the end of this Congress.
Rep. Bill Shuster
(R., Pa.), chairman of the House Transportation Committee, announced Tuesday that he wouldn’t run for re-election. Other term-limited committee chairmen leaving at the end of this year are Reps.
Bob Goodlatte
(R., Va.), chairman of the Judiciary Committee; Jeb Hensarling (R., Texas), chairman of the Financial Services Committee, and
Lamar Smith
(R., Texas), chairman of the House panel on science, space and technology. House Budget Chair
Diane Black
(R., Tenn.) is also leaving to run for governor.

The House Republican conference limits its committee chairman to three consecutive terms, and most of the retiring committee chairmen faced that threshold. An analysis by the Brookings Institution shows that about 40% of committee chairs retire when facing the end of their term.

Mr. Harper wasn’t term-limited. He assumed the Administration Committee chairmanship in January 2017 and became chairman of the Energy & Commerce Subcommittee last month.